In Australian Open, defending champ Stan Wawrinka has easy start

Stan Wawrinka of Switzerland serves to Marsel Ilhan of Turkey during their first round match at the Australian Open in Melbourne, Australia. Wawrinka defeated Ilhan, 6-1, 6-4, 6-2.

Stan Wawrinka of Switzerland serves to Marsel Ilhan of Turkey during their first round match at the Australian Open in Melbourne, Australia. Wawrinka defeated Ilhan, 6-1, 6-4, 6-2. (Lee Jin-man / Associated Press)

Lindsey Vonn provisionally won a super-G on Monday to break Annemarie Moser-Proell's 35-year-old record of 62 World Cup victories. For win No. 63, the American clocked 1 minute, 27.03 seconds down the Olympia delle Tofane course to finish 0.85 seconds ahead of Anna Fenninger of Austria. Tina Weirather...

Lindsey Vonn provisionally won a super-G on Monday to break Annemarie Moser-Proell's 35-year-old record of 62 World Cup victories. For win No. 63, the American clocked 1 minute, 27.03 seconds down the Olympia delle Tofane course to finish 0.85 seconds ahead of Anna Fenninger of Austria. Tina Weirather... (Associated Press)

Nishikori, returning to Grand Slam action for the first time since his run to the U.S. Open final, dropped his opening service game but recovered the break quickly and weathered a difficult opening match.

Nishikori is coming off a big year in 2014, when he became the first Asian man to reach a Grand Slam singles final. He's determined to go one better and win a major.

Two-time champion Victoria Azarenka continued her comeback from a foot injury with a convincing 6-3, 6-2 win over Sloane Stephens and will next have to play U.S. Open finalist Caroline Wozniacki, who beat 18-year-old Taylor Townsend, 7-6 (1), 6-2.